Nivekdodge
Well-known member
Small 1 1/2 story house in Pittsburgh,1200 sq ft. I'm spending a bunch of effort cooling the upstairs. Does anyone have a mini split on the second floor that cools the first floor off "by accident"?
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Mini split upstairs? Will it cool the first floor
- Thread starter Nivekdodge
- Start date
It depends upon the lay-out of the house. There are things you can do to facilitate air circulation. Cold air is heavier than warm air. The airs path will be the staircase as is. You could go to the corners of the rooms and cut holes to the first floor ceiling. That will increase the ability of the air to move and put it in the places you are trying to get cooled. Put them far from your staircase. Air is a fluid and it wants to move or more correctly can be induced to move. Think of your finger over a straw in a glass of water. With the finger on it you can lift the water out of the glass. Remove your finger and the water flows. I would try the passive idea first. If that doesn't work for you try the Tjernlund Air shares. They make floor to floor units and are very good. I've used them on project I was involved in by the thousands for heating and cooling.
Success depends on layout and insulation.
I did a bank barn rehab of an older conversion in eastern PA years ago. Main level and loft. Under the loft was the kitchen and dinning area .. the loft was a bedroom/bath/ shower and about 1/3 of the lower level footprint. The living room area was full height. So the whole space was open.
The installed ducted system was never able to manage the second floor effectively -- we placed a Fujitsu Mini up on the back wall of the loft.
My experience sort of followed what I have heard from others trying to heat and cool with a couple mini-splits. When it was hot out and the second floor naturally required lots of cooling the unit was pumping out cold air and since cold falls -- the lower level would actually get quite cool. Not perfect .. At other times when the load was less .. the lower area would not cool enough or dehumidify.
Now my unit was sized for the upper level load .. but going larger would not help because all that would happen is we would overcool the second floor. Overcooling the second floor when no one was up there -- just to cool the first floor ? Think about that ... is that logical?
Typically -- you need a head at every level. My guess is had I done the conversion from scratch -- it would have been tighter and the loads more even.
How are you cooling the space now ..... and how large is it?
Even in the city w/ 1100 sf -- two floors .... people have two heads
I did a bank barn rehab of an older conversion in eastern PA years ago. Main level and loft. Under the loft was the kitchen and dinning area .. the loft was a bedroom/bath/ shower and about 1/3 of the lower level footprint. The living room area was full height. So the whole space was open.
The installed ducted system was never able to manage the second floor effectively -- we placed a Fujitsu Mini up on the back wall of the loft.
My experience sort of followed what I have heard from others trying to heat and cool with a couple mini-splits. When it was hot out and the second floor naturally required lots of cooling the unit was pumping out cold air and since cold falls -- the lower level would actually get quite cool. Not perfect .. At other times when the load was less .. the lower area would not cool enough or dehumidify.
Now my unit was sized for the upper level load .. but going larger would not help because all that would happen is we would overcool the second floor. Overcooling the second floor when no one was up there -- just to cool the first floor ? Think about that ... is that logical?
Typically -- you need a head at every level. My guess is had I done the conversion from scratch -- it would have been tighter and the loads more even.
How are you cooling the space now ..... and how large is it?
Even in the city w/ 1100 sf -- two floors .... people have two heads
MeentSS02
Well-known member
It depends upon the lay-out of the house.
This sums it up right here. We have a two head mini-split system that cools two upstairs bedrooms...both have minimal impact on the rest of the house, but those rooms stay comfortable year round. Sometimes I notice them a little bit outside of the rooms, but it is only within 1-2 feet of the doors.
If the layout was more open, I'm sure it would have some impact, but that was never our intent.